Forecasts for the 21st Century

Abstract

The population of the world is increasing, mainly in the developing world, and is projected to saturate within about 100 years at up to twice the present population of 6 billion people [1]. Studies [2,3,4] show that, historically, the population growth rate has varied inversely as the annual per capita energy use in most parts of the developing world, where per capita energy use is typically less than 1 tonne of oil equivalent energy per year. However, in areas with more than 2 to 3 tonnes of oil equivalent of energy per year per person the growth rate is around zero. If this trend continues, a stable world population will require, allowing for energy efficiency improvements, some 2 to 3 times the present annual energy use. There is an abundance of energy in the world both exploited and potential to meet this need—fossil, fission, and renewables—but it is not evenly distributed, some is costly, and there are issues of environmental pollution in present use, that may limit use. Fusion energy is a potential longer-term source with attractive environmental features. It is the least developed energy option and still faces a challenging development path, but there are many of areas of the world that would benefit hugely from its deployment from the latter part of the 21st century onward, and it is important to consider how it might be deployed. Most fusion power plant options considered today show an economy of scale, owing to the fixed distance needed for shielding fusion neutrons, tritium breeding and handling the heat loads. One interesting approach is to use the power plant to co-produce electricity and hydrogen to facilitate the introduction of lower cost-of-electricity, multi-gigawatt power plants [5].